The background description provided here is for the purpose of generally presenting the context of the disclosure. Work of the presently named inventors, to the extent it is described in this background section, as well as aspects of the description that may not otherwise qualify as prior art at the time of filing, are neither expressly nor impliedly admitted as prior art against the present disclosure.
Semiconductor processing systems are used to deposit and etch film on substrates such as semiconductor wafers. The semiconductor processing systems include a processing chamber including one or more pedestals for supporting substrates. During processing of the substrates, the pedestals are typically heated. One or more gas mixtures each including one or more process gases may be introduced into the processing chamber and plasma may also be used. When a process is complete, reactants are removed from the processing chamber using purging or evacuation.
Periodically, maintenance is performed on the processing chamber. Prior to performing the maintenance, components of the processing chamber need to cool and reactants need to be completely removed from the processing chamber.
Some substrate processing systems remove reactants by venting the processing chamber to atmosphere using ambient air, pumping to base and then repeating one or more additional times. As used herein, the pump to base includes pumping the processing chamber to a base vacuum pressure usually within a predetermined period. For example only, the pump to base step may have a vacuum pressure that is less than vacuum pressure of a preceding and/or subsequent step. After removing the reactants, the processing chamber is typically left partially open and the processing chamber is allowed to cool.